A company called Vaveliero has developed an iPhone 4 case that gives you easy access to two different mobile accounts.

The kit replaces the iPhone 4’s microSIM tray with an external dual SIM adapter to give the iPhone 4 the capabilities of using two phone accounts from two different carriers. The external SIM is attached inside of the case, making the extra SIM appear like it isn’t even there. The two numbers can be switched in the settings or set on a timer to change as you wish.

Unfortunately, both can’t be used at the same time. We’re also uncertain from the literature if you need to be unlocked to use this with non-supported networks. Vaveliero operates in Europe where locking phones and other douchebaggery is frowned upon. Perhaps in the US, this could be used for a separate AT&T Work and personal account.